1. Field of the Invention
The present invention relates to a semiconductor device of a field effect transistor having a hetero junction and to a method of producing the semiconductor device.
2. Description of the Related Art
Japanese Patent Application Laid-Open No. JP2003-318398 (=JP2003318398) discloses a conventional semiconductor device. According to the above conventional technology, a semiconductor base has a first main face where an N− type silicon carbide epitaxial region 20 is formed on an N+ type silicon carbide substrate 10. An N− type polycrystalline silicon region 60 contacts the first main face, allowing the epitaxial region 20 and the N− type polycrystalline silicon region 60 in combination to form a hetero junction. Moreover, adjacent to a junction face between the epitaxial region 20 and the N− type polycrystalline silicon region 60, a gate electrode 40 is formed via a gate insulating film 30.
The N− type polycrystalline silicon region 60 is connected to a source electrode 80, while the N+ type silicon carbide substrate 10 has a backface formed with a drain electrode 90.